update packages

[CreaPhase.git] / octave_packages / m / statistics / distributions / binocdf.m

diff --git a/octave_packages/m/statistics/distributions/binocdf.m b/octave_packages/m/statistics/distributions/binocdf.m
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+## Copyright (C) 2012 Rik Wehbring
+## Copyright (C) 1995-2012 Kurt Hornik
+##
+## This file is part of Octave.
+##
+## Octave is free software; you can redistribute it and/or modify it
+## under the terms of the GNU General Public License as published by
+## the Free Software Foundation; either version 3 of the License, or (at
+## your option) any later version.
+##
+## Octave is distributed in the hope that it will be useful, but
+## WITHOUT ANY WARRANTY; without even the implied warranty of
+## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+## General Public License for more details.
+##
+## You should have received a copy of the GNU General Public License
+## along with Octave; see the file COPYING.  If not, see
+## <http://www.gnu.org/licenses/>.
+
+## -*- texinfo -*-
+## @deftypefn {Function File} {} binocdf (@var{x}, @var{n}, @var{p})
+## For each element of @var{x}, compute the cumulative distribution function
+## (CDF) at @var{x} of the binomial distribution with parameters @var{n} and
+## @var{p}, where @var{n} is the number of trials and @var{p} is the
+## probability of success.
+## @end deftypefn
+
+## Author: KH <Kurt.Hornik@wu-wien.ac.at>
+## Description: CDF of the binomial distribution
+
+function cdf = binocdf (x, n, p)
+
+  if (nargin != 3)
+    print_usage ();
+  endif
+
+  if (!isscalar (n) || !isscalar (p))
+    [retval, x, n, p] = common_size (x, n, p);
+    if (retval > 0)
+      error ("binocdf: X, N, and P must be of common size or scalars");
+    endif
+  endif
+
+  if (iscomplex (x) || iscomplex (n) || iscomplex (p))
+    error ("binocdf: X, N, and P must not be complex");
+  endif
+
+  if (isa (x, "single") || isa (n, "single") || isa (p, "single"));
+    cdf = zeros (size (x), "single");
+  else
+    cdf = zeros (size (x));
+  endif
+
+  k = isnan (x) | !(n >= 0) | (n != fix (n)) | !(p >= 0) | !(p <= 1);
+  cdf(k) = NaN;
+
+  k = (x >= n) & (n >= 0) & (n == fix (n) & (p >= 0) & (p <= 1));
+  cdf(k) = 1;
+
+  k = (x >= 0) & (x < n) & (n == fix (n)) & (p >= 0) & (p <= 1);
+  tmp = floor (x(k));
+  if (isscalar (n) && isscalar (p))
+    cdf(k) = 1 - betainc (p, tmp + 1, n - tmp);
+  else
+    cdf(k) = 1 - betainc (p(k), tmp + 1, n(k) - tmp);
+  endif
+
+endfunction
+
+
+%!shared x,y
+%! x = [-1 0 1 2 3];
+%! y = [0 1/4 3/4 1 1];
+%!assert(binocdf (x, 2*ones(1,5), 0.5*ones(1,5)), y);
+%!assert(binocdf (x, 2, 0.5*ones(1,5)), y);
+%!assert(binocdf (x, 2*ones(1,5), 0.5), y);
+%!assert(binocdf (x, 2*[0 -1 NaN 1.1 1], 0.5), [0 NaN NaN NaN 1]);
+%!assert(binocdf (x, 2, 0.5*[0 -1 NaN 3 1]), [0 NaN NaN NaN 1]);
+%!assert(binocdf ([x(1:2) NaN x(4:5)], 2, 0.5), [y(1:2) NaN y(4:5)]);
+
+%% Test class of input preserved
+%!assert(binocdf ([x, NaN], 2, 0.5), [y, NaN]);
+%!assert(binocdf (single([x, NaN]), 2, 0.5), single([y, NaN]));
+%!assert(binocdf ([x, NaN], single(2), 0.5), single([y, NaN]));
+%!assert(binocdf ([x, NaN], 2, single(0.5)), single([y, NaN]));
+
+%% Test input validation
+%!error binocdf ()
+%!error binocdf (1)
+%!error binocdf (1,2)
+%!error binocdf (1,2,3,4)
+%!error binocdf (ones(3),ones(2),ones(2))
+%!error binocdf (ones(2),ones(3),ones(2))
+%!error binocdf (ones(2),ones(2),ones(3))
+%!error binocdf (i, 2, 2)
+%!error binocdf (2, i, 2)
+%!error binocdf (2, 2, i)
+